<template>
	<!-- 筛选区 -->
   <div class="sub-filter" v-if="filterData && !filterLoading">
     <div class="item">
       <div class="head">品牌：</div>
       <div class="body">
         <a  @click="changeBrand(brand.id)" :class="{active:filterData.selectedBrand===brand.id}" href="javascript:;" v-for="brand in filterData.brands" :key="brand.id">{{brand.name}}</a>
       </div>
     </div>
     <div class="item" v-for="p in filterData.saleProperties" :key="p.id">
         <div class="head">{{p.name}}:</div>
         <div class="body">
             <a @click="changeProp(p,prop.id)" :class="{active:p.selectedProp===prop.id}" href="javascript:;" v-for="prop in p.properties" :key="prop.id">{{prop.name}}</a>
         </div>
     </div>
   </div>
   <div v-else class="sub-filter">
    <CsSkeleton class="item" width="800px" height="40px"  />
    <CsSkeleton class="item" width="800px" height="40px"  />
    <CsSkeleton class="item" width="600px" height="40px"  />
    <CsSkeleton class="item" width="600px" height="40px"  />
    <CsSkeleton class="item" width="600px" height="40px"  />
   </div>
</template>
<script>
import { findSubCategoryFilter } from '@/api/category'
import { ref,watch } from 'vue'
import { useRoute } from 'vue-router'
export default {
  name: 'SubFilter',
  setup(props, { emit }) {
      // 1.获取数据
      // 2.数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
      // 3.完成渲染
      const route = useRoute()
      const filterData = ref(null)
      const filterLoading = ref(false)
      // 4.分类发现变化的时候需要重新获取筛选数据，需要使用侦听器
      watch(() => route.params.id,(newVal) => {
          // 当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
          if(newVal && `/category/sub/${newVal}` === route.path) {
              filterLoading.value = true
              // 发请求获取数据
              newVal && findSubCategoryFilter(route.params.id).then(({result}) => {
                  // 品牌全部
                  result.selectedBrand = null
                  result.brands.unshift({id:null,name:'全部'})
                  // 销售属性全部
                  result.saleProperties.forEach(p =>{
                      p.selectedProp = undefined
                      p.properties.unshift({id:null,name:'全部'})
                  })
                  // 设置修改的数据
                  filterData.value = result
                  filterLoading.value = false
              })
          }
      },{immediate:true})

            
      // 获取筛选参数
      const getFilterParams = () => {
          const obj = { brandId: null, attrs: [] }
          // 品牌
          obj.brandId = filterData.value.selectedBrand
          // 销售属性
          filterData.value.saleProperties.forEach(item => {
            if (item.selectedProp) {
              const prop = item.properties.find(prop => prop.id === item.selectedProp)
              obj.attrs.push({ groupName: item.name, propertyName: prop.name })
            }
          })
          // 参考数据：{brandId:'',attrs:[{groupName:'',propertyName:''},...]}
          if (obj.attrs.length === 0) obj.attrs = null
          return obj
      }

      // 选择品牌
      const changeBrand = (brandId) => {
        if(filterData.value.selectedBrand === brandId) return
        filterData.value.selectedBrand = brandId
        emit('filter-change', getFilterParams())
      }

      // 选中属性
      const changeProp = (p,attrId) => {
        if(p.selectedProp === attrId) return
        p.selectedProp = attrId
        emit('filter-change', getFilterParams())
      }

      return { filterData,filterLoading,changeBrand,changeProp }
  }
}
</script>
<style scoped lang='less'>
  // 筛选区
  .sub-filter {
    background: #fff;
    padding: 25px;
    .item {
      display: flex;
      line-height: 40px;
      .head {
        width: 80px;
        color: #999;
      }
      .body {
        flex: 1;
        a {
          margin-right: 36px;
          transition: all .3s;
          display: inline-block;  
          &.active,
          &:hover {
            color: @xtxColor;
          }
        }
      }
    }
  }
.cs-skeleton {
  padding: 10px 0;
}
</style>